Squared staircase baluster



FIG. 1 is a side elevational view of a squared staircase baluster showing my new design, the broken line showing is for illustrative purposes only and forms no part of the claimed design; and

FIG. 2 is an end elevational view thereof, the broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a squared staircase baluster, as shown and described. 